Frist, let me quote another post I made in Sound & Shine:
I have noticed two things since I posted this: First, 99% of the time it begins to hum when I press on the brake. Second, it does not matter if the car/engine is hot or cold.
Early this morning I was leaving a friend's house and I started the car to let it warm up. As it idled (in Park) I noticed a high pitched whirr. This is nothing new, I believe I have heard this before. But I noticed that if I pressed on the brake the whirr dropped in pitch.
This caused me to wonder if this whirr was my alternator, and if I possibly have a bad alternator and this is what is causing this problem with my stereo system. I believe the alternator is the stock unit that came with the car in 1994. So does anyone know if this is what could be causing my problem?
Some other minor points:
Since that first quoted post I have grounded all my stereo components to the same piece of metal in the dash. One ground is a few inches away from the others but I dont think it would be enough to cause a ground loop.
Second, I have ordered a new (well, used) front amp off of eBay in case that's what is causing the problem. The two rear amps were replaced last year.
There are only two other things which I can think of that could be causing the radio noise, though I dont know how likely either are.
First, I have noticed that the AM/FM antenna wire runs pretty close to the stereo grounds and the amplifier near the head unit.
Second, I have different brands of brake pads on the front and rear brakes. The front are stock and the rear are some aftermarket brand. I don't see how this could be affecting anything but I think I have read something about the car being grounded through the brakes and tires.
If anyone has ANY idea what I can do to fix this please let me know. This thing is driving me crazy!
Hi. I have a 1994 Mustang GT. It came with the Mach 460 stereo system. I have replaced the head unit and used wiring harnesses provided by Crutchfield to wire in the power and amplifier connections. Every once in a while I will get what seems to be alternator noise in the system. I know its not the new head unit as it used to do this with the old factory head unit, which I had to replace because the volume buttons stopped working. It does not hum all the time. Sometimes it will not hum at all, most times it will start as I am driving. I have noticed that alot of times it will start humming when I am on the brake, either stopped or coming to a stop. Turning the radio on and off usually corrects the problem, at least temporarily. Also I'm not sure whether car temperature plays a role. I know it will hum when the car is warm, not sure if it would happen when the car has just been started. I have checked the connectors and they seem to be ok. I've tried checking the grounds but the only ones I could find were the two near the battery and one on the other side of the front engine bay. I know there is one near the inside instrument panel fuse box but I haven't been able to locate it yet, so I dont know if thats my problem. If anybody knows anything that would help, or a way to correct it please let me know. If you have questions or need more info let me know and I'll reply as soon as possible. Thanks!
I have noticed two things since I posted this: First, 99% of the time it begins to hum when I press on the brake. Second, it does not matter if the car/engine is hot or cold.
Early this morning I was leaving a friend's house and I started the car to let it warm up. As it idled (in Park) I noticed a high pitched whirr. This is nothing new, I believe I have heard this before. But I noticed that if I pressed on the brake the whirr dropped in pitch.
This caused me to wonder if this whirr was my alternator, and if I possibly have a bad alternator and this is what is causing this problem with my stereo system. I believe the alternator is the stock unit that came with the car in 1994. So does anyone know if this is what could be causing my problem?
Some other minor points:
Since that first quoted post I have grounded all my stereo components to the same piece of metal in the dash. One ground is a few inches away from the others but I dont think it would be enough to cause a ground loop.
Second, I have ordered a new (well, used) front amp off of eBay in case that's what is causing the problem. The two rear amps were replaced last year.
There are only two other things which I can think of that could be causing the radio noise, though I dont know how likely either are.
First, I have noticed that the AM/FM antenna wire runs pretty close to the stereo grounds and the amplifier near the head unit.
Second, I have different brands of brake pads on the front and rear brakes. The front are stock and the rear are some aftermarket brand. I don't see how this could be affecting anything but I think I have read something about the car being grounded through the brakes and tires.
If anyone has ANY idea what I can do to fix this please let me know. This thing is driving me crazy!